Endometriosis is a condition where tissue similar to the lining inside the uterus grows outside of it, often on organs like the ovaries, fallopian tubes, and the outer surface of the uterus. This condition frequently causes chronic pelvic pain, particularly during menstrual periods, and can also lead to heavy bleeding or difficulty conceiving. Diagnosing endometriosis is complex, with many individuals experiencing delays in receiving an accurate diagnosis.
Understanding Ultrasound in Endometriosis Diagnosis
Ultrasound is an imaging technique using high-frequency sound waves to create real-time images of internal body structures. A transducer emits these waves, and their echoes are converted into visual representations. This non-invasive method is a common first-line imaging tool in gynecology.
Pelvic ultrasounds are performed in two ways: transabdominal, where the transducer moves over the lower abdomen, and transvaginal, where a slender transducer is inserted into the vagina. Both approaches provide detailed views of the reproductive organs. Ultrasound helps assess pelvic pain, often prompting investigation for conditions like endometriosis.
What Ultrasound Imaging Can Detect
Ultrasound can identify certain forms of endometriosis. A key example is endometriomas, also known as “chocolate cysts.” These ovarian cysts are filled with old, dark blood and are typically visible on an ultrasound scan.
Beyond ovarian cysts, specialized ultrasound, especially when performed by experienced sonographers or gynecologists, can detect signs of deep infiltrating endometriosis. This form involves lesions grown more than 5 millimeters deep into tissues. These deeper lesions may be identified in locations like the bowel, bladder, or rectovaginal septum, appearing as irregular thickening or other anomalies.
When Ultrasound May Not Show Endometriosis
Despite its utility, ultrasound has limitations in detecting all forms of endometriosis. The most common type, superficial peritoneal endometriosis, consists of small implants on the surface of pelvic organs. These lesions are often not visible on ultrasound because they are too small, too flat, or blend seamlessly with surrounding tissues. Therefore, a “normal” ultrasound result does not rule out endometriosis.
Even deep infiltrating endometriosis can be missed if lesions are not in typical locations or if the ultrasound is not conducted by an expert. Factors like bowel gas can interfere with image clarity, making detection challenging. The sonographer’s skill and experience greatly influence the accuracy of endometriosis detection via ultrasound.
A Comprehensive Diagnostic Approach
Diagnosing endometriosis involves more than just an ultrasound scan. A thorough clinical evaluation is essential, starting with a detailed discussion of symptoms, including pain characteristics and their relation to the menstrual cycle. A physical examination also provides clues, as healthcare professionals may feel for unusual changes or tender areas in the pelvis.
Other imaging techniques, such as Magnetic Resonance Imaging (MRI), may be used in specific circumstances. MRI can provide more detailed images, especially for mapping deep infiltrating endometriosis before surgery. However, a definitive diagnosis often requires a minimally invasive surgical procedure called laparoscopy. During laparoscopy, a surgeon can directly visualize and often remove endometrial implants, providing both diagnosis and treatment. The diagnostic process integrates various pieces of information to reach a conclusive diagnosis.